Wood, metal and cement are well-known materials used for fabricating flower pots. Wood is particularly desirable because of its beauty and the fact that it is easily cut and shaped with hand tools into flower pots of any shape or size and when exposed to the sun, wooden containers will gradually fade in color to a uniform grey. Wood, however, has two main disadvantages. It is expensive and it will decay over time. Even the exotic and expensive woods like cedar and redwood will decay eventually so it is desirable, if possible, to find some way to use less expensive wood or to extend the life of the more exotic wood containers.
In the past people have sought to extend the life of wooden containers with metal liners, but metal has several disadvantages of it's own. First it does not breathe. Plant roots need oxygen, and though this can be compensated for by providing non-compacted growing medium and plenty of drainage some plants will not thrive in metal containers. Also, metal containers will release metal ions into the soil. This is particularly detrimental with copper liners but zinc and iron can also be detrimental to some plants. It has also been substantiated that protective metal liners may trap water against the wood, promoting decay and sometimes discoloring the wood.
Containers formed of cast cement have the disadvantage of being heavy and, because of their thickness, often they do not breathe any better than metal containers.